The invention belongs to the technical field of digital instrument equipment monitoring, and particularly relates to a digital audio and video signal transmission processing equipment link fault analysis and alarm method, which comprises the following steps of: 1, converting an equipment link into N DAGs; 2, marking an alarm signal node; 3, performing breadth-first traversal on the DAG which is being processed, and sorting alarm signal nodes into a set C1; 4, using an independent path search algorithm for the set C1; and 5, if the number N of the DAGs in the data structure G in the step 1 is greater than 1, repeating the steps 2-4, finding out a fault path and a fault source in each DAG, and ending the algorithm. The fault source can be accurately analyzed and positioned, the processing efficiency is improved, a user can be helped to rapidly find the fault source, the fault response time is shortened, the safety of the whole system is improved, fault alarm information display can be optimized, and the user cannot receive a lot of disordered alarm information.